During the last two decades, Haemophilus influenzae serotype a (Hia) emerged as an important cause of invasive disease in Canadian First Nations and Inuit, and Alaskan Native populations, with the highest rates reported in young children. Immunocompetent adults, in contrast to children, do not typically develop invasive Hia disease. To clarify factors responsible for an increased burden of invasive Hia disease in certain population groups we studied serum bactericidal activity (SBA) against Hia and quantified IgG and IgM specific to Hia capsular polysaccharide in healthy adult members of two First Nations communities: 1) with reported cases of invasive Hia disease (Northern Ontario, NO), and 2) without reported cases (Southern Ontario, SO), in comparison to non-First Nations living in proximity to the NO First Nations community, and non-First Nations elderly non-frail Canadians from across the country (total of 110 First Nations and 76 non-First Nations). To elucidate the specificity of bactericidal antibodies, sera were absorbed with various Hia antigens. Naturally acquired SBA against Hia was detected at higher rates in First Nations (NO, 80%; SO, 96%) than non-First Nations elderly Canadians (64%); the SBA titres in First Nations were higher than in non-First Nations elderly Canadians (P0.05). Among First Nations, SBA was mediated predominantly by IgM, and by both antibodies specific to Hia capsular polysaccharide and lipooligosaccharide.
The SBA against Hia is frequently present in sera of First Nations adults regardless of the burden of Hia disease observed in their community; it may represent part of the natural antibody repertoire, which is potentially formed in this population under the influence of certain epigenetic factors. Although the nature of these antibodies deserves further studies to understand their origin, the data suggest that they may represent important protective mechanism against invasive Hia disease.
This paper examines search and rescue and backcountry medical response constraints in the Canadian Arctic and potential for unmanned aerial vehicles (UAV) to aid in response and preparedness. Semi-structured interviews (n = 18) were conducted with search and rescue responders, Elders, and emergency management officials to collect data on current emergency response and potential for UAV use. UAV test flights (n = 17) were undertaken with community members. We analyzed five years of weather data to examine UAV flight suitability. Numerous challenges face Arctic search and rescue and backcountry emergency response. Changing social and environmental conditions were described as increasing vulnerability to backcountry emergencies. Responders desired additional first aid and emergency training. Legal and weather restrictions were found to limit where, when and who could fly UAVs. UAVs were demonstrated to have potential benefits for hazard monitoring but not for SAR or medical response due to legal restrictions, weather margins, and local capacity. We find that communities are ill-prepared for ongoing SAR demands, let alone a larger disaster. There are numerous limitations to the use of consumer UAVs by Arctic communities. Prevention of backcountry medical emergencies, building resilience to disasters, and first responder training should be prioritized over introducing UAVs to the response system.